[Study on testicular tissue in animals with congenital hormone deficiency]

Of 3 kinds of animals with congenital hormone deficiency, i.e., mouse with Snell pituitary dwarfism (dw) in which hypoplasia of the pituitary anterior lobe is seen from embryonal stage and which almost lacks in growth hormone (GH), prolactin (PRL), thyroid stimulating hormone (TSH) and adrenocorticotrophic hormone (ACTH); mouse with little dwarfism lacking only in GH (lit); and mouse with congenital primary hypothyroidism in which the thyroidal gland shows hypoplasia, thyroxine (T4) in blood is not measurable and, conversely, TSH level is abnormally high (hyt), the males of dw/dw and hyt/hyt have been proved to be infertile, but it is little known about lit/lit. After performing early recovery experiment by administering GH + T4 to dw/dw, GH to lit/lit and T4 to hyt/hyt from birth, the testicles of 40-day-old mice were investigated morphologically in the normal control group, non-treated group and treated group in order to clarify the relation between hormones and the sperm-generating potency. The total number of sperm-generating cells, which consist of spermatogonia, spermatocytes, spermatids and sperms, showed remarkable decreases, compared with each control group, and the decrease in total cell number was improved favorably by treatment with hormone. In comparison with the control groups, significant decreases were showed in the spermatid number for the dw/dw group, sperm number for the lit/lit group, and spermatid and sperm numbers for the hyt/hyt group. These results indicate that GH and T4 have a potential effect on sperm-generating function.